Nonlinear Waves Seminar - Brad Hindman

About this event

Brad Hindman, Department of Applied Mathematics, University of Colorado Boulder

Rotation and Convection: How the Coriolis Force Can Lead to Traveling Wave Convection

Stars and planets have more in common than you might initially think. All stars and planets rotate and most convect. We all have a physical intuition of convection that comes from boiling pots of water, rising thermals, etc. In all such cases, hot blobs of fluid rise straight up and cold blobs fall straight down. In this talk I will describe what happens to convection when the convecting object spins rapidly. Oddly, the convection can actually be stabilized by the Coriolis force, forming a wave that propagates longitudinally, with hot spots that rise but also deflect laterally. This type of "overstable" wave is called a thermal Rossby wave. "Thermal" because it's a form of thermal convection and "Rossby" because it has a close kinship with the Rossby waves that are observed in the Earth's atmosphere and oceans. I will discuss the conditions that allow this type of wave to exist, how the wave's restoring force operates, and where we might expect such waves to be found. Along the way, I will discuss other waves for which the Coriolis force acts as the restoring force, including the eponymous Rossby waves that I previously mentioned.